THe PKCR033W is a white ribbed non child resistant certified cap with a neck size of 33MM. This cap has HS035 pulp liner (HS035 is an induction seal liner and is used with induction sealing equipment. A thin layer of liner material is electromagnetically activated by the induction sealing machine.) This liner has a backing thickness of .025 and has "sealed for your protection" in red printed on the top of the liner. This is a universal liner and works with plastic and glass bottles.